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Since I recently moved last year to the suburbs of Phoenix Az. Summertime temps can range in 104 to 113 degrees Sent the car in spring to a well-known Corvette shop in Texas. They did a heads and cam package. The car came back to me and is overheating 215-220+ I sent the car back. they put an $800 Dewitt radiator and a $800 high performance 2900rpm fan once the temps get over 100 degrees it starts to reach 215-220 again. Any Ideas? Do you think I need to put a high output water pump? Thanks Tim
Since I recently moved last year to the suburbs of Phoenix Az. Summertime temps can range in 104 to 113 degrees Sent the car in spring to a well-known Corvette shop in Texas. They did a heads and cam package. The car came back to me and is overheating 215-220+ I sent the car back. they put an $800 Dewitt radiator and a $800 high performance 2900rpm fan once the temps get over 100 degrees it starts to reach 215-220 again. Any Ideas? Do you think I need to put a high output water pump? Thanks Tim
did this well known shop install a 160* thermostat and tune the fans to come on earlier? is a fuse possibly blown? although 215-220 is not technically overheating
I agree in town but @ speed should drop down to 200ish
Not necessarily. That's not what I experienced with the stock radiator. And I had that car for six years.
EDIT: I was just looking at the service manual, and the engine won't even go into overtemp (Overheated Engine Protection Operating Mode) until it hits 270 degrees for over 10 seconds. Fans won't go full-on until 225 degrees. Thermostat starts to open at 188 degrees and should be fully open at 206 degrees.
I witnessed first-hand on my Z06 when the fan connector melted and it went into overtemp.
Last edited by VetteVinnie; Sep 7, 2022 at 11:39 PM.
Engine is a heat pump. It converts fuel into heat. If you make it more efficient by adding horse power goodies, it will make more heat. There is no getting away from it. You now have to find ways to get rid of more heat from the cooling system but 220 is not excessive, the cooling system is designed to handle that with ease.
You don't state the driving conditions. The DeWitts rad gives you 50% more cooling capacity, so if there are no obstructions, your temps should have come down while cruising on the highway. If they didn't, unless the shop cleaned the AC condensor, they get clogged over time with sand, bugs, dirt, and lower the air flow through the rad. There are a few posts that report a 10 degree drop in hwy temps just from cleaning the condensor.
If you've seeing those temps in the city, that makes sense because it's all about air flow. Then you're reliant on the fan and fan table programming. If you don't have the air flow through the rad, a 160 t-stat won't do anything for you, either.
I also live in Metro Phoenix. My 2007 427 C-6 (not a ZO6, but has the 427) has an A & A S/C and A to A intercooler which restricts the air flow to the radiator to a degree. 220-230 degrees is NOT overheating when it comes to our summertime temps in the Valley of the Sun. I have the stock radiator and cooling fan and was about to install a new radiator and fan set-up, but decided to give Purple Ice radiator super coolant a try. I drained the radiator, and used 50/50 antifreeze and began with one bottle of the Purple Ice ($8.99 at O'Reilly's) and tested the result. It did help the engine temp about 4-5 degrees. Added another bottle of Purple Ice, and it helped an additional 4-5 degrees. So I went for one more bottle and now runs about 215 on a 110 degree day. It definitely helped and as I previously stated, and all this without changing the radiator or the cooling fan. You have nothing to lose, give it a shot and see if it won't help. Any questions, PM me.
I must add......when I installed the S/C and had the front of the engine exposed, I decided to change the water pump (AC Delco which come with a 185 degree thermostat), all the hoses, and even the power steering pump. The new water pump made absolutely no difference in engine temps. The reason I'm saying this is the previous thermostat was a 160 degree. These LS engine are designed to run "hot" to a point. In my research on the subject I found that the emissions were part of the reason to run 220-230 degrees. That being said you are not overheating the engine running at 220-225 in Phoenix in the summer.
did this well known shop install a 160* thermostat and tune the fans to come on earlier? is a fuse possibly blown? although 215-220 is not technically overheating
Yes they did do both! I'm asking because I really don't feel like spending over $3000 in round trip shipping for a third time if I can figure it out and have it done here.
You don't state the driving conditions. The DeWitts rad gives you 50% more cooling capacity, so if there are no obstructions, your temps should have come down while cruising on the highway. If they didn't, unless the shop cleaned the AC condensor, they get clogged over time with sand, bugs, dirt, and lower the air flow through the rad. There are a few posts that report a 10 degree drop in hwy temps just from cleaning the condensor.
If you've seeing those temps in the city, that makes sense because it's all about air flow. Then you're reliant on the fan and fan table programming. If you don't have the air flow through the rad, a 160 t-stat won't do anything for you, either.
They replaced the radiator with the Dewitt made for high performance engines and their brand new to the market with one large fan now with 2900rpm's also a new condenser! Something you said, triggered my brain to go out and check, if the front air deflector was missing and it's not there!!! There is a Front Driver Side Bumper Outer Valance Panel and passenger side too! even though it doesn't say it directly the way they are designed I seriously think they also deflect the air flow through the radiator! I think " Problem solved!!" Thank you Thank you!!!
Base. Helps protect vehicle from dirt or debris\ \ Made of durable material\ \ This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors
You don't state the driving conditions. The DeWitts rad gives you 50% more cooling capacity, so if there are no obstructions, your temps should have come down while cruising on the highway. If they didn't, unless the shop cleaned the AC condensor, they get clogged over time with sand, bugs, dirt, and lower the air flow through the rad. There are a few posts that report a 10 degree drop in hwy temps just from cleaning the condensor.
If you've seeing those temps in the city, that makes sense because it's all about air flow. Then you're reliant on the fan and fan table programming. If you don't have the air flow through the rad, a 160 t-stat won't do anything for you, either.
reading all your posts helped me solve the problem! Thank you so very much!!
I must add......when I installed the S/C and had the front of the engine exposed, I decided to change the water pump (AC Delco which come with a 185 degree thermostat), all the hoses, and even the power steering pump. The new water pump made absolutely no difference in engine temps. The reason I'm saying this is the previous thermostat was a 160 degree. These LS engine are designed to run "hot" to a point. In my research on the subject I found that the emissions were part of the reason to run 220-230 degrees. That being said you are not overheating the engine running at 220-225 in Phoenix in the summer.
If they had wanted the engines to run 220+ they would have used a 210 degree t-stat, not the 187 that shipped with them. They also wouldn’t have programmed the fan to start ramp up at 199. If the fan is on at all at hwy speeds, all that’s doing is wasting gas. Running the fan isn’t for free.
And I know 106 isn’t quite 110, but headed into Barstow doing say 60 on Route 66 and with the DeWitts rad, I was seeing 195 - 196, which was what I saw most any time at highway speeds up to 85 going across the Texas panhandle.
What I was discussing with 210-225 temps in Phoenix in the summer is in stop and go traffic, not at highway speeds. With the S/C and air to air intercooler on my car, even with the STOCK radiator and fan my freeway temps are 190-200........if I didn't have the intercooler and the S/C I'm sure the temps would be less. Actually before I installed the blower and intercooler it would run 190-200 in traffic in the summer. I fabricated a small diffuser that is placed directly in front of the radiator (it's about 2" and curved up to avoid road parking lot speed bumps and intersection dips) (my car is lowered a bit), and that too made a difference in a bit of extra cooling on the freeway. If my car will run 215-225 degrees in heavy stop and go traffic in Phoenix in the summer, I'm VERY happy and didn't need to spend $3k to do so.
What I was discussing with 210-225 temps in Phoenix in the summer is in stop and go traffic, not at highway speeds. With the S/C and air to air intercooler on my car, even with the STOCK radiator and fan my freeway temps are 190-200........if I didn't have the intercooler and the S/C I'm sure the temps would be less. Actually before I installed the blower and intercooler it would run 190-200 in traffic in the summer. I fabricated a small diffuser that is placed directly in front of the radiator (it's about 2" and curved up to avoid road parking lot speed bumps and intersection dips) (my car is lowered a bit), and that too made a difference in a bit of extra cooling on the freeway. If my car will run 215-225 degrees in heavy stop and go traffic in Phoenix in the summer, I'm VERY happy and didn't need to spend $3k to do so.
Thanks for the clarification. I'd be interested if you could share the details of your home built diffuser. Part of the problem in responding to questions is that quite often insufficient information is provided. 215 -- 225 in stop and go traffic makes sense, because that's what the fan table programming is set up to do. What you don't state is what t-stat you have installed, or if you've altered the fan table. If it's the OEM 187 and stock fan table, it's surprising to me that you would ever see 190 in traffic, unless it's before everything has heated up. I guess there's so many variables. I've got extra cooling with the DeWitts, but then again I've got an oil cooler and tranny cooler sitting in front blocking some of the air flow, and a front license plate that blocks flow as well.
Air diverters to hopefully divert more air directly from the radiator.
Attached is the pic of the small air diverter I fabricated underneath the car. It is bolted to the lower radiator support. Also, today I just finished fabricating 2 additional "plates" attached to the plate that is part of the S/C application. (also attached). I did this to see if they will help "push" the air from the radiator fan in a more direct flow to the front of the engine. I will see later today if they help even more. This is the air diverter that I fabricated to help move more air to the front of the radiator. Today I fabricated 2 plates to possibly divert more air to the front of the engine. Obviously this plate is on the passenger side of the S/C This added air diverter plate is on the drivers side of the air intake.
Over heating
[img]data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAA AABCAQAAAC1HAwCAAAAC0lEQVR42mN8Vw8AAmEBb 87E6jIAAAAASUVORK5CYII=[/img] 2004-08. Base. Z06, zr1, 427 & grand sport. 2009. Helps keep engine running cool\ Maximizes air flow through the radiator\ This GM Genuine Part is designed, engineered, and tested to rigorous standards and is backed by General Motors
[img]data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAEAA AABCAQAAAC1HAwCAAAAC0lEQVR42mN8Vw8AAmEBb 87E6jIAAAAASUVORK5CYII=[/img]
